Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stanford researchers study how gene level variations in blood affect immunity

13.02.2003


Differences in people seem to run in the blood, according to a recent study that examines which genes are active in blood cells. The work, published in this week’s online issue of the Proceedings of the National Academy of Sciences, found that the levels of several genes used by blood cells vary from person to person.



"Nobody had taken this broad a look at genetic variation in the blood of healthy people," said David Relman, MD, associate professor of medicine at Stanford and a co-author of the study.

People vary greatly in their reactions to bacteria and viruses; some individuals fall prey to every bug that comes along while others go through winter sniffle-free. Relman, along with Patrick Brown, PhD, professor of biochemistry, and research assistant Adeline Whitney thought these differences might show up when looking at which genes are active in circulating blood cells.


To find out the extent and nature of the differences in gene activity in people’s blood, Relman and his colleagues drew blood from 75 healthy people and extracted a molecule called RNA. RNA is produced by active genes and can be used to identify which genes are being expressed in a given sample. They then attached a fluorescent molecule to the RNA and applied the samples to a gene chip - a glass slide dotted with human genes. If a sample contained RNA corresponding to a gene on the chip, the fluorescently labeled RNA would bind to the spot and produce a visible signal. The bigger the signal, the more RNA was present, and therefore the greater the gene expression. Whitney then compared which spots varied in brightness among the samples.

The blood used in this analysis contained a variety of cells, including red blood cells that carry oxygen to the tissues and immune cells that fight disease. The red blood cells don’t contain nuclei and therefore don’t produce RNA. That leaves immune cells as the only cells making RNA in the blood sample. Any differences found in the pattern of active genes resulted from these disease-fighting cells.

A few genes stood out as being used at varying levels in different people. Some of these could be used to distinguish between men and women. For example, women use different levels of genes whose proteins respond to an immune protein called interferon. Researchers had suspected that genes in the interferon pathway might have a role in the higher risk of autoimmune diseases among women.

The researchers also found variations in two genes that weren’t previously documented as being active in blood cells. One is a gene that makes the prion protein - the protein altered in people who have Creutzfeldt-Jakob disease. Another surprisingly variable gene was BRCA1, which is mutated in an inherited form of breast cancer. It could turn out that levels of the prion protein or BRCA1 in the blood play some role in determining the risk for prion-related diseases or cancer.

In addition to the variation of gene expression among different people, the researchers found genes that varied according to the time of day that blood was drawn. Other genes were used at higher or lower levels depending upon the age of the blood donor - a finding that could eventually help doctors understand why older people are more prone to some illnesses.

Relman pointed out that it’s too early to know why people use genes at higher or lower levels in blood cells, and the consequences of this variability. "It may be that some people confronted a virus or had a cold the week before, or had different environmental experiences," he said.

He added that despite the differences, there was remarkable similarity in the genes used in the blood cells among the study subjects. "It was surprising that the degree of variability was as small as it turns out to be," he said. This finding bodes well for using gene expression in blood to distinguish between healthy people and those with an infectious disease. Because people are usually quite similar, any disease-related variation should stand out.


Other Stanford researchers who contributed to the paper include MD/PhD students Maximillian Diehn, PhD, and Ash Alizadeh, PhD; postdoctoral fellow Stephen Popper, DSc; and medical student Jennifer Boldrick.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children’s Hospital at Stanford. For more information, please visit the Web site of the medical center’s Office of Communication & Public Affairs at http://mednews.stanford.edu.

PRINT MEDIA CONTACTS: Amy Adams at (650) 723-3900 (amyadams@stanford.edu)
BROADCAST MEDIA CONTACT: Neale Mulligan at (650) 724-2454 (nealem@stanford.edu)

Neale Mulligan | EurekAlert!
Further information:
http://med-www.stanford.edu/MedCenter/MedSchool/

More articles from Health and Medicine:

nachricht Millions through license revenues
27.04.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>